The trouble with brain scans

Many of the methods on which brain scan studies are based have been flawed — as one image of a dead salmon proved

By Vaughan Bell / The Guardian, London

Recent advances have tried to control these problems but researchers have become much more cautious. “Our default attitude to any new and interesting fMRI finding should be skepticism,” says Tal Yarkoni, a neuroscientist at the University of Colorado. “What’s particularly problematic,” he says, “is the amount of flexibility researchers have when performing their analyses ... you have no idea how many things the researchers tried before they got something to work.” Psychologist Russ Poldrack, from the University of Texas, who has been at the forefront of correcting these issues, also highlights cultural issues. This flexible approach “also includes methods that are known by experts to be invalid, but unfortunately these still get into top journals, which only helps perpetuate them.” Yarkoni explains that “researchers have a big incentive to come up with exciting new findings,” meaning scientists are motivated to “torture” the data and journals are attracted by the media-friendly results.

In this light of this, stories about the discovery of “brain centers” fall flat and efforts to base public policy on brain scans become nothing short of ridiculous. But perhaps the most important problem is not that brain scans can be misleading, but that they are beautiful. Like all other neuroscientists, I find them beguiling. They have us enchanted and we are far from breaking their spell.

Vaughan Bell is visiting senior research fellow at the Institute of Psychiatry, King’s College London